Each and every U.S. and foreign patent and patent application, inclusive of the German priority patent application Serial No. 198 56 413.9 filed Dec. 8, 1998, identified in the specification of the present application is to be considered as being incorporated herein by reference.
The invention relates to improvements in methods of and in apparatus for regulating the permeability of tubular wrappers of rod-shaped commodities, e.g., of the envelopes of plain or filter cigarettes or other rod-shaped smokers"" products. More particularly, the invention relates to improvements in methods of and in apparatus for increasing the permeability of tubular wrappers with laser beams or with beams of other suitable high-energy penetrative radiation.
It is known to perforate selected portions of tubular wrappers of rod-shaped smokers"" products (e.g., plain or filter cigarettes and hereinafter referred to as filter cigarettes) with one or more laser beams which are focussed upon selected portions of the wrappers while the filter cigarettes roll about their respective axes. In many instances, the filter cigarettes are caused to roll during sidewise movement through a rolling channel which is bounded by a surface of a stationary rolling member and a surface of a moving rolling member (e.g., a conveyor which advances successive filter cigarettes of a series of such cigarettes sideways toward, along and beyond the combined rolling and perforating station).
Reference may be had, for example, to U.S. Pat. No. 4,281,670 (granted Aug. 4, 1981 to Heitmann et al. for xe2x80x9cAPPARATUS FOR INCREASING THE PERMEABILITY OF WRAPPING MATERIAL FOR ROD-SHAPED SMOKERS"" PRODUCTSxe2x80x9d). The patented apparatus employs a source of one or more laser beams which are focussed upon successive rolling cigarettes while the cigarettes are caused to move sideways by a drum-shaped conveyor and are compelled to roll in response to engagement with a rolling member, e.g., a moving belt, a rotating drum or the like. Since a cigarette which is caused to rotate about its axis is compelled to simultaneously move sideways from the inlet to the outlet of a rolling channel, the means for focussing the laser beam or beams upon the wrapper of the cigarette in the rolling channel must be capable of causing the beam or beams to move with the rolling cigarette. In order to ensure that a laser beam which impinges upon the wrappers of cigarettes in the rolling channel will perforate selected portions of successive wrappers in a predictable manner, it is necessary to ensure that the angular (rolling) and sidewise movements of each cigarette entering the rolling channel are identical to those of previously or subsequently treated cigarettes. This necessitates a pronounced frictional engagement between the wrapper of a cigarette in the rolling channel on the one hand, and the surfaces which bound the rolling channel on the other hand. At least one of these surfaces is caused to move relative to the other surface. Pronounced frictional engagement between the wrapper of a cigarette and the rolling surfaces is apt to cause deformation (even bursting) and/or defacing of the tubular wrapper.
An object of the invention is to provide an apparatus which is constructed and assembled and which can be operated in such a way that, even though successive rod-shaped articles which are caused to advance through the rolling station are compelled to move in a highly predictable fashion, they are treated gently and are caused to change their permeabilities in an optimum manner.
Another object of the invention is to provide the apparatus with novel and improved means for moving successive rod-shaped articles through the rolling station.
A further object of the invention is to provide an apparatus which can properly perforate the tubular wrapper of a cigarette or another rod-shaped smokers"" product even though the beam or beams of radiation need not penetrate though the rod-shaped filler (such as a filler of tobacco and/or filter material for tobacco smoke) of the commodity in the rolling channel.
An additional object of the invention is to provide a simple, compact and reliable apparatus which can be utilized in production lines (e.g., for the making and packing of filter cigarettes) as a superior substitute for presently known perforating apparatus.
Still another object of the invention is to provide an apparatus wherein the rod-shaped articles are caused to enter into and to rotate in the rolling channel in a novel and improved way.
A further object of the present invention is to provide an apparatus which ensures gentle but highly predictable treatment of successive rod-shaped articles during the important stages including entry into and movement out of the rolling station.
Another object of the instant invention is to provide the apparatus with novel and improved means for moving rod-shaped articles sideways toward, through and beyond the rolling station.
An additional object of the invention is to provide a novel and improved method of manipulating cigarettes or other rod-shaped products preparatory to, during and following changes in the permeability of their tubular wrappers.
Still another object of the invention is to provide a novel and improved method of increasing the permeabilities of tubular wrappers of filter cigarettes of unit length or multiple unit length.
A further object of the invention is to provide a method of guiding and moving successive rod-shaped articles, such as filter cigarettes, during transition from sidewise movement to combined sidewise and rolling movement and/or vice versa.
Another object of the invention is to provide novel and improved means for rolling successive ones of short or long series of rod-shaped articles about their respective axes.
An additional object of the present invention is to provide an apparatus which can simultaneously perforate several selected portions of tubular wrappers of rod-shaped smokers"" products, e.g., in a filter rod making machine, in a cigarette making machine, in a filter cigarette making machine (known as tipping machine), in a cigarette packing machine, or in a path between two successive machines of the above outlined character.
One feature of the present invention resides in the provision of an apparatus for increasing the permeability of a tubular wrapper of an elongated rod-shaped article, e.g., a filter cigarette of double unit length wherein a filter mouthpiece of double unit length is located between two plain cigarettes of unit length and wherein a change of permeability normally involves the making of perforations in the wrapper of the mouth-piece prior to subdivision of the article into two filter cigarettes of unit length.
The improved apparatus comprises a first rolling member and a second rolling member which is movable realative to the first rolling member. The rolling members respectively have first and second rolling surfaces which define at least one rolling channel having a height such that, as a result of movement of the second rolling member relative to the first rolling member and upon entry into the at least one channel, the article is compelled to roll about its axis and to move sideways from the inlet to the outlet of the at least one channel. This can be readily accomplished by selecting the height of the at least one channel (i.e., the distance between the first and second rolling surfaces) in such a way that it is only slightly less than the diameter of the article.
The apparatus further comprises a source of at least one beam of high energy radiation (e.g., a laser beam and hereinafter called beam of penetrative radiation), means (e.g., a suitable optical system) for focussing the at least one beam along at least one path defined at least in part by one of the rolling members and upon the wrapper of the article in the at least one rolling channel, and means for conveying the article toward the inlet and away from the outlet of the at least one rolling channel. In accordance with a feature of the invention, the second rolling member comprises at least one flexible element having a portion which is located within the conveying means.
The first rolling member is or can be stationary and the at least one flexible element can constitute an endless flexible element (e.g., an endless belt) The conveying means can comprise a rotary wheel- or drum-shaped conveyor.
The apparatus preferably further comprises means (such as one or more pulleys or rollers) for guiding the aforementioned portion of the at least one flexible element along a path which extends between the inlet and the outlet of the at least one rolling channel and wherein the article is disengaged from the conveying means and is free to roll about its axis as a result of contact with the rolling surfaces.
The means for guiding the at least one flexible element can include at least 2n rollers or pulleys (n is the number of rolling channels). The conveying means can be provided with at least one recess for the rollers or pulleys of the guide means.
In accordance with a presently preferred embodiment, the apparatus comprises first and second guide rollers which are respectively located at the inlet and at the outlet of the at least one rolling channel and are respectively rotatable about first and second axes (preferably about two parallel axes). The aforementioned portion of the at least one flexible element is adjacent the at least one rolling channel and is arranged to disengage the article from the conveying means and to maintain the article in contact with the first rolling surface, and the axes of the two guide rollers are spaced apart from each other a distance which at least matches the circumferential length of the article in the at least one channel to thus ensure that the article completes at least one full revolution about its longitudinal axis while it rolls during advancement from the inlet to the outlet of the at least one rolling channel.
The aforementioned first guide roller can be said to constitute means for effecting a transfer of the article from the conveying means (e.g., from an axially parallel flute provided in the periphery of a rotary drum- or wheel-shaped conveyor) onto the aforementioned portion of the at least one flexible element at the inlet of the at least one rolling channel, and the second guide roller can be said to constitute or to form part of a means for effecting a transfer of the article from the at least one flexible element onto the conveying means (e.g., into an oncoming empty flute of the rotary conveyor) at the outlet of the at least one rolling channel.
The conveying means is or can be arranged to transport the article sideways along an elongated path extending toward, through and beyond the at least one rolling channel. The apparatus employing such conveying means can further comprise a third rolling member which is adjacent the elongated path downstream of the outlet of the at least one rolling channel and defines with the second rolling member a second rolling channel. The second rolling member cooperates with the third rolling member to cause the article to roll about its axis during sidewise movement through the second channel, and such apparatus further comprises a second source of at least one second beam of penetrative radiation as well as means for focussing the at least one second beam along at least one path which is defined (at least in part) by the second and/or third rolling member and upon the wrapper of the article rolling in the second channel. Such apparatus renders it possible to provide two different portions of the tubular wrapper of a rod-shaped article (such as the wrapper of the filter mouthpiece of the aforediscussed filter cigarette of double unit length) with two sets of perforations in two successive stages or steps.
Alternatively, and if the conveying means includes means for transporting along the aforementioned elongated path a series of successive articles, one of the articles of such series can be caused to roll in the at least one channel while another article of the series is caused to roll in the second channel.
The aforementioned portion of the at least one flexible element which constitutes or forms part of the second rolling member is preferably guided in such a way that it maintains the article out of contact with the conveying means while the article is caused to roll in the at least one rolling channel.
The first rolling member is or can be stationary, and the at least one path for the at least one beam of penetrative (such as coherent) radiation can be defined, at least in part, by at least one opening or window which is provided in the first rolling member.
The at least one channel is or can constitute a linear (i.e., at least substantially straight) channel.
At least one of the rolling surfaces bounding the at least one rolling channel can include a curved portion in the region of the inlet and/or outlet of the at least one rolling channel. It is often preferred to provide the at least one curved portion on the first rolling surface such curved portion can constitute a concave portion of the respective rolling surface. The center of curvature of the curved portion of one of the rolling surfaces (normally the first rolling surface) is or can be located on the axis of the aforementioned guide roller at the inlet or outlet of the at least one rolling channel.
The first and second rolling members can define a second rolling channel which is aligned with the at least one rolling channel, and such apparatus can further comprise a source of at least one second beam of penetrative radiation as well as means for focussing the at least one second beam upon a second portion of the article rolling in the second channel while a first portion of such article rolls in the at least one channel.
The at least one channel can include mutually inclined first and second sections which are respectively adjacent the inlet and the outlet of the channel. The second rolling surface of the apparatus employing such channel is preferably provided with a curved intermediate zone between the two mutually inclined sections of the channel. Such apparatus can further comprise first and second guide rollers (e.g., pulleys) one of which is adjacent the second rolling surface at the inlet and the other of which is adjacent the second rolling surface at the outlet of the channel. A third guide roller can be installed adjacent the intermediate zone of the second rolling surface and the flexible element is trained over such guide rollers. The first rolling surface can include a median portion which is complementary to and confronts the intermediate zone; such median portion and the intermediate zone preferably define a channel portion of constant width.
The focussing means of the just outlined modified apparatus can comprise means for focussing the at least one beam of penetrative radiation along a single path upon the wrappers of successive articles rolling in the second section of the at least one channel.
Alternatively, the source of radiation can include means for generating first and second beams of penetrative radiation, and the focussing means of such apparatus can comprise first and second focussing units which respectively direct the first and second beams of penetrative radiation upon the wrappers of successive articles rolling in the first and second sections of the at least one channel.
The first and second sections of the rolling channel can make an obtuse angle, e.g., an angle which equals or approximates 150xc2x0.
It is presently preferred to construct and assemble the improved apparatus in such a way that the rolling members constitute the only means for moving articles in the rolling channel from the inlet to the outlet; the at least one flexible element of the second rolling member is driven by a suitable prime mover in order to cause successive articles to roll along the first rolling surface in a direction to cause successive articles to advance toward the outlet of the channel.
Another feature of the present invention resides in the provision of a method of perforating (i.e., of changing the permeability of) a tubular wrapper of an elongated rod-shaped article with at least one laser beam or another beam of high-energy penetrative radiation. The improved method comprises the steps of conveying the article sideways along a first path (e.g., along a portion of a circular path), moving the article sideways from the first path into a second path, rolling the article in the second path, focussing the at least one beam of radiation upon the wrapper of the article rolling in the second path, and returning the article from the second path into the first path (or moving the article from the second path into a third path which may but need not form part of the first path).
The focussing step can include simultaneously or seriatim directing a plurality of beams of penetrative radiation upon longitudinally spaced apart portions of the wrapper of the article while the article is being rolled in the second path.
The method can further comprise the steps of moving the articles sideways from the second path into a third path, rolling the articles in the third path, and focussing at least one beam of penetrative radiation upon the wrapper of the article rolling in the third path prior to the returning step.
The focussing step can include focussing two beams of penetrative radiation upon two discrete articles rolling in two mutually inclined portions of the second path. Alternatively, the focussing step can include focussing the at least one beam of penetrative radiation upon successive articles rolling in only one of two mutually inclined successive sections of the second path.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved permeability increasing apparatus itself, however, both as to its construction and the modes of assembling and utilizing the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawings.